There are many planting techniques currently practiced by farmers. Under a conventional process, planting of a field is carried out in steps. First, the entire field is worked to break up the soil, break loose the residue from the preceding year's crops, and break down and work the residue into the tilled soil. The planting rows in the prior year are eliminated so that the entire field has a substantially homogenous soil texture.
This conventional technique has numerous drawbacks. First of all, this technique requires the performance of multiple steps to effect planting of the field. The field is first cultivated during one or more passes of a cultivator over the field. A separate planter attachment is then utilized to deposit seed and spray fertilizer in an entirely separate operation. To carry out the different operations, the user is required to connect and disconnect equipment to and from towing vehicle.
A further problem with this conventional technique is that the residue, such as corn stalks, may not be effectively pulverized, even though several passes are made over the field with the cultivator unit. The result is that the residue may jam up in the planter unit and/or block the placement of the seed and spraying of fertilizer.
A further problem with this conventional technique is that cultivation of the entire field increases soil erosion from both rain and wind. Not only is this undesirable from the standpoint of loosing fertile soil, but of late the federal government has imposed restrictions on erosion by requiring that a certain amount of ground cover remain in place at all times in the field.
Certain of these problems led to the development of residue clearing devices which facilitate the planting of seed without prior cultivation. The John Deere Company, for one, has been active in the development of such residue clearing devices. One such structure currently offered by John Deere has a cooperating pair of rotary wheels. The wheels are constructed from flat steel plate material and have a solid central body with radially projecting teeth spaced equidistantly about the periphery of the body. A highly successful wheel design is commercially available through the assignee herein under the trademark TRASHWHEEL™. Each wheel pair is mounted on a planter frame so that the teeth on the wheel pair are in mesh, with the wheels toed in at their bottoms and diverging away from each other in a trailing direction. The angular relationship of the wheels results in their being automatically rotated as they engage with and are dragged through soil in operation.
The wheels are oriented so that they resituate residue in the planting row upstream of a “V-opener”, which defines an open seed slot. The frame that carries the wheels also carries a supply of fertilizer and/or seed, with the seed being deposited in the open slot as the frame is advanced. Once the seed is placed, a downstream pair of closing wheels redeposits soil in the slot created by the V-opener.
Heretofore, the residue clearing wheels have been operated at a depth so as not to penetrate as deeply as the seed slot. Consequently, the V-opener operates on primarily unloosened soil. In moist soil, the V-openers tend to create the slot primarily by compaction of the soil against the walls bounding the slot. When the closing wheels replace soil in the seed slot, much of the soil remains in a compacted state at the walls. The result is that less loose soil than is desirable is placed back in the slot.
As a consequence of this, the seed may not be fully covered or covered with only a thin layer of soil. Alternatively, even if the seed is initially covered with soil by the closing wheels, the soil, upon drying out, tends to develop cracks through which the seed is directly exposed to the elements. The seed may be destroyed by, for example, direct exposure to the sun. Alternatively, if fertilizers are subsequently placed on the sod, the fertilizer may be applied in substantial quantities directly upon the seed, with adverse results.
Heretofore, since there has been no practical solution to the above problem, those in the art have merely contended with this problem. The result of this is that crop quality and quantity are often significantly compromised. This is particularly a problem in today's environment in which it is imperative that yield be maximized for farmland.